一个二级联动

<div class="layui-form-item">
        <label class="layui-form-label">所属级别：</label>
        <div class="layui-input-inline">
            <input type="hidden" id="nitemtype" name="nitemtype" value="" />
            @*@html.dropdownlistfor(m => m.meid, menuhelper.getme(), new { @jqverify = "required", @jqerror = "请选择级别" })**@
           //循环插入
            <select name="itemselect" id="itemselect" lay-filter="itemselect" @(type != 0 ? "disabled" : "")>
                <option value="0">选择级别</option>
                @{
                    //foreach (doingstudy.entity.news_menu imodel in new doingstudy.repository.news_menu().iqueryable("menuid", 0))

                    foreach (doingstudy.entity.news_menu imodel in new doingstudy.repository.news_menu().iqueryable("pid", 0))
                    {
                        string skey = string.empty;
                        if (nmenuid == imodel.menuid)
                        {
                            skey = " selected=\"selected\" ";
                        }
                        <option @skey value="@imodel.menuid">@imodel.menuname</option>
                    }
                }
            </select>
        </div>
        <div class="layui-input-inline">
            <select name="professionid" id="professionid">
                @{
                    <option value="0">全部 </option>
                    if (nmenuid != 0)
                    {
                        list<doingstudy.entity.news_menu> nmodel = new doingstudy.repository.news_menu().findlist("pid", nmenuid);
                        for (var i = 0; i < nmodel.count; i++)
                        {
                            string skey2 = string.empty;
                            if (existid == nmodel[i].menuid)
                            {
                                skey2 = " selected=\"selected\" ";
                            }
                            <option @skey2 value="@nmodel[i].menuid">@nmodel[i].menuname</option>
                        }
                    }

                }
            </select>
        </div>

<script>  
    layui.use('myform');   
    layui.use("form", function () {
        var form = layui.form();
        form.on('select(itemselect)', function (data) {
            fillcity(data.value);
          
            document.getelementbyid('nitemtype').value = $("#itemselect").val();
        });

        //资讯类型
        form.on('radio(newstype)', function (data) {
          
            if (data.value == 3) {
                $("#divvideo").show();
            } else {
                if (data.value == 0) {
                    $("#divphoto").hide();
                }
                else {
                    $("#divphoto").show();
                }
                $("#divvideo").hide();
            }
        });
    });
    function fillcity(provinceid) {
        $.ajax({
            url: "/newsmanage/news/getmodulechildlist?pid=" + provinceid,
            type: "get",
            datatype: "json",

            success: function (cities) {
                $("#professionid").html("");
               
                $.each(cities, function (i, city) {
                    $("#professionid").append(("<option value='" + city.value + "'>" + city.text + "</option>"));
                });
                layui.use("form", function () {
                    var form = layui.form();
                    form.render();
                });
            }
        });
    }
   

</script>

[httpget]
        public string getmodulechildlist(int pid)
        {
            return system.web.mvc.menuhelper.getmodule(pid).tojson();
        }//get请求

[httpget]
public actionresult jsonlist()
{
int itemselect = converthelper.saferequest("itemselect",0);//一级
int professionid = converthelper.saferequest("professionid", 0);//二级
int smenuid = 0;
if (professionid != 0)
{
smenuid = professionid;
}
else {
smenuid = itemselect;
}
string stitle = converthelper.safestring(request["txttitle"], "");
pagemodel page = pagemodelinstance.getinstance();
page.pagesize = pagesize;
page.pageindex = nowpage;
datatable dtlist = new doingstudy.repository.news_news().getlist(stitle, snewstype, smenuid, 0, isaudit, ishead, pagesize, nowpage, out rowscount);
[httppost]
public actionresult edit(doingstudy.entity.news_news model)
{
doingstudy.repository.news_news adminrep = new doingstudy.repository.news_news();
int itemselect = converthelper.saferequest("itemselect", 0);//一级
int professionid = converthelper.saferequest("professionid", 0);//二级
if (professionid != 0)
{
model.menuid = professionid;
}

 效果图如图所示；